Demonstrators with raised arms are heckled by supporters of Republican presidential candidate Donald Trump as they are ejected from his campaign rally in Fayetteville, N.C., on March 9, 2016. (REUTERS/Jonathan Drake)

Many American commentators have had trouble understanding the rise of Donald Trump. How could such a figure surge to become the most likely standard-bearer for the GOP – much less have any chance of entering the White House?

But Trump is far from unique. As many commentators have noted, he fits the wave of authoritarian populists whose support has swelled in many Western democracies.

The graph below from ParlGov data illustrates the surge in the share of the vote for populist authoritarian parliamentary parties (defined as rated 8.0 or above by experts on left-right scales) across 34 OECD countries.

On April 21, 2002, Jean-Marie Le Pen defeated France’s socialist Prime Minister Lionel Jospin in the first round of the French presidential elections. That shocked Europe. One of the best-known radical right leaders, Le Pen dismissed the Holocaust as a “detail of history.” All over France, millions of people protested at massive anti-Front National demonstrations.

Less than three weeks later, on May 6, 2002, Netherland’s flamboyant and controversial Pim Fortuyn was assassinated for his anti-immigrant and anti-Muslim views, leading to a sudden surge of support for his party in the general election. The anti-immigrant Lijst Pim Fortuyn, formed just three months before the election, suddenly became the second largest party in the Dutch parliament and part of the governing coalition.

Nor are these isolated successes. During the last two decades, parties led by populist authoritarian leaders have surged in popularity in many nations, gaining legislative seats, reaching ministerial office, and holding government power.

It’s not just Europe, either. Latin America has its radical populism, with charismatic leaders like Hugo Chavez in Venezuela and Evo Morales in Bolivia.

Some populist leaders and parties rise temporarily in opinion polls then plummet equally rapidly. In Britain, for example, the UK Independence Party won only a single seat in the May 2015 general election. But even flash parties can infect the political culture and mainstream parties; the UKIP fueled more rabid anti-European sentiments, and was one of the reasons Conservatives called the EU Brexit referendum.

These parties steal votes mainly from the center right. Populist appeals also draw support from certain characteristics associated with the center left, especially by appealing predominately to men, the less educated, and the economically marginalized.

Why is angry populism on the rise?

The standard economic account explains populism as arising when growing inequality and social exclusion mobilize the dispossessed. But populist authoritarian leaders have arisen in several affluent post-industrial “knowledge” societies, in cradle-to-grave welfare states with some of the best-educated and most secure populations in the world, like Sweden and Denmark — where you’d expect social tolerance and liberal attitudes instead of xenophobic appeals.

Some observers have offered U.S.-based explanations for Trump in particular, arguing that his popularity is a reaction to the election (and reelection) of the first African-American president to the White House; a backlash against Obama’ policies and style; public anger against fat cats in elections; or the tea party tilt pushing House Republicans to the right. But populists have gained in many modern democracies without any of this.

These authoritarian populists have been with us now for 20 years, in economically bad times as well as good, in both predominately Catholic and Protestant societies, in Nordic and Mediterranean regions, in liberal Norway and conservative Switzerland, in egalitarian welfare states as well as unequal societies, in the European Union and in several Anglo-American democracies like New Zealand, Canada, and Australia. Why?

We’re seeing a deep and strong a cultural backlash against changes in social values

Here’s why. Populist authoritarianism can best be explained as a cultural backlash in Western societies against long-term, ongoing social change.

Over recent decades, the World Values Survey shows that Western societies have been getting gradually more liberal on many social issues, especially among the younger generation and well-educated middle class. That includes egalitarian attitudes toward sex roles, tolerance of fluid gender identities and LGBT rights, support for same-sex marriage, tolerance of diversity, and more secular values, as well as what political scientists call emancipative values, engagement in directly assertive forms of democratic participation, and cosmopolitan support for agencies of global governance.

This long-term generational shift threatens many traditionalists’ cultural values. Less educated and older citizens fear becoming marginalized and left behind within their own countries.

In the United States, evidence from the World Values Survey perfectly illustrates the education gap in these types of cultural values. Well before Trump, a substantial and striking education gap can be observed in American approval of authoritarian leaders. The WVS asked whether Americans approved of “having a strong leader who doesn’t have to bother with congress or elections.” The figure below shows a consistent education gap and growing support for this statement since 2005.

Most remarkably, by the most recent wave in 2011, almost half — 44 percent — of U.S. non-college graduates approved of having a strong leader unchecked by elections and Congress.

DATA: World Values Survey

This deeply disturbing finding reflects attitudes usually observed in states such as Russia.

Moreover, this is not an isolated finding or quirk of fieldwork. If we look at a couple of the classic measures of tolerance toward sexual liberalization and value change – including toward homosexuality and abortion – the two figures below illustrate the size of the education gap on these issues.

Finding a gap is hardly headline news in the research literature. But the education gap appears to widen slightly over time. That suggests that U.S. differences in cultural values and social tolerance by educational status have expanded rather than shrunk.

DATA: World Values Survey.

DATA: World Values Survey.

The Republican Party has prepared the way for an authoritarian movement

By giving voice to and amplifying fears of cultural change, the Republicans have opened the way for a populist leader. Trump’s support appears to be fueled by a backlash among traditionalists (often men and the less educated) faced with rising American support for issues such as gay marriage, sexual equality, and tolerance of social diversity, all lumped under the phrase “political correctness.” Looking back, we can see precursors to the Trump movement, like the tea party.

Whether or not Trump is elected, he and his followers have articulated a new brutalism and intolerance, altering what’s speakable in American politics.

While the Trump phenomenon mirrors what’s happened elsewhere, most Western parliamentary democracies have many safeguards in place, so that even when populist authoritarian parties surge, they remain limited in seats and thus real power.

At the March 11 debate in Miami, Republican presidential candidate Donald Trump was asked about fights at his events. Here are some examples of the physical altercations that have occurred at rallies for Trump in recent months. (Monica Akhtar/The Washington Post)

Pippa Norris is the McGuire lecturer in comparative politics at the John F. Kennedy School of Government at Harvard University and the ARC Laureate Fellow and professor of government and international relations at the University of Sydney.

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